/*******************************************************************************************
 * Copyright (c) 2006-7 Laboratorio di Sistemi di Elaborazione e Bioingegneria Informatica *
 *                      Universita' Campus BioMedico - Italy                               *
 *                                                                                         *
 * This program is free software; you can redistribute it and/or modify it under the terms *
 * of the GNU General Public License as published by the Free Software Foundation; either  *
 * version 2 of the License, or (at your option) any later version.                        *
 *                                                                                         *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY         *
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A         *
 * PARTICULAR PURPOSE. See the GNU General Public License for more details.                *
 *                                                                                         *
 * You should have received a copy of the GNU General Public License along with this       *
 * program; if not, write to the:                                                          *
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,                    *
 * MA  02111-1307, USA.                                                                    *
 *                                                                                         *
 * --------------------------------------------------------------------------------------- *
 * Project:  Capwap                                                                        *
 *                                                                                         *
 * Author :  Ludovico Rossi (ludo@bluepixysw.com)                                          *
 *           Del Moro Andrea (andrea_delmoro@libero.it)                                    *
 *           Giovannini Federica (giovannini.federica@gmail.com)                           *
 *           Massimo Vellucci (m.vellucci@unicampus.it)                                    *
 *           Mauro Bisson (mauro.bis@gmail.com)                                            *
 *******************************************************************************************/

#include "CWCommon.h"

#ifdef DMALLOC
#include "../dmalloc-5.5.0/dmalloc.h"
#endif

int gCWForceMTU = 0;
int gCWRetransmitTimer = CW_RETRANSMIT_INTERVAL_DEFAULT;	//Default value for RetransmitInterval
int gCWNeighborDeadInterval = CW_NEIGHBORDEAD_INTERVAL_DEFAULT;	//Default value for NeighbourDeadInterval (no less than 2*EchoInterval and no greater than 240)
int gCWMaxRetransmit = CW_MAX_RETRANSMIT_DEFAULT;	//Default value for MaxRetransmit

int CWTimevalSubtract(struct timeval *res, const struct timeval *x, const struct timeval *y)
{
	int nsec;
	struct timeval z = *y;

	// Perform the carry for the later subtraction by updating Y
	if (x->tv_usec < z.tv_usec) {
		nsec = (z.tv_usec - x->tv_usec) / 1000000 + 1;
		z.tv_usec -= 1000000 * nsec;
		z.tv_sec += nsec;
	}
	if (x->tv_usec - z.tv_usec > 1000000) {
		nsec = (x->tv_usec - z.tv_usec) / 1000000;
		z.tv_usec += 1000000 * nsec;
		z.tv_sec -= nsec;
	}
	// Compute the time remaining to wait. `tv_usec' is certainly positive
	if (res != NULL) {
		res->tv_sec = x->tv_sec - z.tv_sec;
		res->tv_usec = x->tv_usec - z.tv_usec;
	}
	// Return 1 if result is negative (x < y)
	return ((x->tv_sec < z.tv_sec) || ((x->tv_sec == z.tv_sec) && (x->tv_usec < z.tv_usec)));
}